In hosiery manufacturing, the pre-boarding of thick raw socks constitutes a critical step for dimensional stability and contour formation; workers mount the unbleached, undyed thick-knit sock blanks onto metal forms matching specific sizes and styles, then subject them to high-temperature steam setting equipment. Under controlled heat (typically higher than for thin hosiery) and steam pressure, the fibers undergo thermoplastic deformation, allowing the sock structure to fully expand and fix its shape—establishing precise morphology essential for subsequent dyeing and final boarding processes.